Prying attachment for shovels



6, 1957 c. w. GARDNER PRYING ATTACHMENT FOR SHOVELS 2 Sheets-Sheet 1 Filed Oct. 15, 1954 INVENTOR. 6///4/?LE5 W. 6/4 RDA EA 4 TTOIRNE'YS Ill 1957 c. w. GARDNER 2,801,758

PRYING ATTACHMENT FOR SHOVELS Filed Oct. 15, 1954 2 Sheets-Sheet 2 INVENTOR. /a UMRLES 14 GARDNER A TTORNEYS United States Patent PRYING ATTACHMENT FOR SHOVELS Charles Gardner, Peoria Heights, 11]., assignor to Caterpillar Tractor Co., Peoria, 111., a corporation of "California Application October 15, 1954, Serial No. 462,476

2 Claims. Cl. 214-140 This invention relates to hydraulically controlled shovels which are mounted on tractors or other vehicles and particularly to a prying attachment on the bucket, or load-receiving means.

It is common practice to mount a power shovel on a track-type tractor, or a wheeled vehicle, and to provide the shovel with a pair of lift arms and either one, or a pair, of tilt arms. Both the lift arms and the tilt arms may be, and usually are, actuated by hydraulic cylinders.

In certain types of loading operations, it is necessary to first pry the material, or objects to be loaded, loose from the earth or from packed, or cemented, aggregate. Examples of these types of operations are prying large boulders or logs loose from the ground; breaking up concrete pavings; and prying loose solidified material, such as slag from iron and steel producing furnaces.

This prying action of the bucket or other load receiving means, which is mounted on the lift and tilt arms, may be obtained at its forward edge by operation of the tilt cylinder to cause the bucket to rock about the pivotal connection of the bucket on the lift arms. Since the tilt cylinders are usually of small size and the lift cylinders are comparatively larger in size, it is advantageous to utilize the greater power from the lift cylinders to achieve more prying action at the forward edge of the bucket. However, the bucket is not usually so designed that force available from the lift cylinders may be utilized to rock the bucket about a fulcrum to result in prying action at the forward edge.

It is an object of this invention to provide a conventional bucket or other load receiving means, of a hydraulically controlled shovel, which is mounted on a vehicle, with means to utilize the greater force of the lift cylinders, thereby achieving a greater prying action at the forward edge of the load receiving means.

It is another object of this invention to provide a method of retracting the aforementioned means whenever it is desirable. Further and more specific objects and advantages of the invention are made apparent in the following specification by reference to the accompanying drawings.

In the drawings:

Fig. 1 is a side view of a conventional track-type tractor having a hydraulically actuated shovel mounted thereon, comprising a conventional bucket secured to lift and tilt arms, the said bucket being provided with toothlike extensions embodying the present invention;

Fig. 2 is a perspective view of the bucket showing the tooth-like extensions permanently secured to the bucket;

Fig. 3 is a perspective view of the bucket showing the tooth-like extensions secured to the sides of the bucket by hinges and retained in their extended position by locking means;

Fig. 4 is a side view of the bucket secured to the lift and tilt arms showing the bucket in a loading position and the tooth-like extensions hinged to sides of the bucket and locked in an extended position; and

Fig. 5 is similar to Fig. 4 showing the extensions locked in a retracted position.

Referring to Fig. 1, a track-type tractor is shown at 10 as having a power shovel mounted thereon. The tractor mounted shovel comprises a bucket or load receiver 11 secured to a pair of lift arms 12 as by pivot pins 13. The lift arms are pivotally connected to the tractor at 14 and are raised and lowered upon actuation of a pair of lift cylinders, one of which is shown at 15. In like manner a pair of tilt arms 16 are pivotally se-" cured at 17 to the bucket 11 and are also pivotally connected to the tractor and to a pair of tilt cylinders, one of which is shown at 18, by means of a lever 19. Both the lift cylinders 15 and the tilt cylinders 18 are pivotally mounted on the tractor at 15a and 18a respectively.

A large variety of lift and tilt arm arrangements are found among the many commercially available vehicle mounted hydraulic shovels. However, in most types, the bucket may be rocked about the pivotal supports on the lift'arrns by actuating the tilting mechanism.

To achieve a prying action at the forward edge 11a of the bucket 11, regardless of the particular type of lift and tilt arm linkage, the bucket must first be tipped forwardly. With a power shovel having a linkage as shown in Fig. 1, the bucket 11 is tipped forwardly by extending the tilt cylinders 18 which causes the bucket to rock about the lift arm bucket pivot 13 in a clockwise direction. The forward edge 11a is then forced under an object to be pryed loose by forward movement of the tractor. The tilt cylinders are then retracted to cause the bucket to rock in a counter-clockwise direction about the pivot 13 and to cause the forward edge 11a to rise. The prying action or force attained at the forward edge of the bucket is therefore limited by the capacity of the tilt cylinders.

Since the lift cylinders are usually of a larger size than the tilt cylinders, it is advantageous to utilize them in obtaining more prying action; however, a fulcrum point and a short moment arm of a lever are not present in the conventional bucket. The lift arms 12 travel in an are about the pivot point 14 on the tractor in raising and lowering the bucket, and to obtain a prying action from this movement, the present invention provides an extension on the bucket which will rest on the ground to act as a fulcrum and also extend forwardly of the fulcrum point to act as a short moment arm.

If the entire forward edge of the bucket were projected forwardly to provide this fulcrum point and short moment arm in achieving this prying action, the resulting bucket design would be inefiicient in other digging, loading, and dumping operations. Therefore this invention provides extensions at the sides of the bucket as fulcrum points and short moment arms which permit the utilization of the lift cylinders in a prying operation without hindering other functions of the power shovel.

A tooth-like extension, shown at 20, is secured to each side of the bucket. An initial fulcrum, indicated at f and a short-moment arm indicated at m,- are thereby provided.

In prying with a bucket provided with tooth-like extensions 20, shown in Fig. 1, the bucket is tipped forwardly as described above, and the forward ends 20a of the extensions are then forced under the object to be pried. The tilt cylinders 18 may then be retracted to rock the bucket rearwardly about the pivot 13; however, the lift cylinders 15 may be retracted simultaneously to cause the bucket to rock about the fulcrum f, thereby utilizing the combined force of the lift and tilt cylinders to. achieve a maximum prying action.

It may be seen that the initial fulcrum point may be varied by changing the degree of forward tilt of the bucket before the ends 2001 of the extensions 20 are forced under an object to be pried. Thus, the mechanical advantage of the lever action may be selectively varied within the limits of bucket tilt.

In Fig. 2, the tooth-like members 20 are shown as permanently secured to the sides of the bucket 11 as by welding or other suitable means. In no way do these members interfere with the loading of loose material; howeverthey may interfere in digging compacted material, such as earth in its natural state. Therefore, means are provided to retract the members 20 when it is not desirable to use them. Such means are shown in Figs. 3, 4, and 5 and comprise hinge connections indicated at 21 between the members 20 and the sides of the bucket and locking means such as a hasp-type retaining mechanism indicated at 22. When it is desired to dig and load a material without the use of the members 20, they may be conveniently swung to positions at the sides of the bucket as shown in Fig. 5 and secured in this retracted position by another retaining mechanism indicated at 23. It is also possible to remove the members 20 entirely by withdrawing the pintles of the hinges 21.

I claim:

1. A prying attachment for a power actuated shovel or the like which comprises a forwardly extending and upwardly curved member adjacent the forward edge of the load receiving means of the shovel adapted to be placed under an object to be pried with the curved portion of the member resting on the ground whereby leverage may be applied by downward movement of the load receiving means.

2. In a vehicle mounted material handling device having load receiving means pivotally secured to lift arms and tilt arms, said armsbeing pivotally connected to the vehicle, and hydraulic cylinders secured to the vehicle to selectively actuate said lift and tilt arms, forwardly projecting extensions hinged to the load receiving means to engage the ground and enable a prying action upon downward movement of-the load receiving means and locking means to secure said extensions in either an extended or retracted position.

References Cited in the file of this patent UNITED STATES PATENTS 1,466,464 Beatty Aug. 28, 1923 2,439,122 Baker Apr. 6, 1948 2,603,374 McNamara July 15, 1952 

